4 Super Silvertone 12A8 12A8GT Vacuum Tubes Valves Lot Of Four

4 Super Silvertone 12A8 12A8GT Vacuum Tubes Valves Lot Of FourThese four Super Silvertone 12A8GT tubes were tested for shorts, gas and transconductance on our Paul Hart calibrated TV7 U and measured as follows: 32, 32, 36 and 48 where minimum (65%) is 29. WE HAVE SCORES OF THOUSANDS OF VACUUM TUBES. IF IT'S NOT LISTED, WE MAY HAVE IT. PLEASE ALSO SEE OUT ETSY SISTER SITE "LOWTECHTWOO" AND OR CALL OR TEXT US AT 202 372 6931 IF YOU DO NOT SEE WHAT YOU NEED OR HAVE ANY QUESTIONS. 1. MOST FORMS OF SHIPPING EXCEPT

Tube Two probably has a piece of broken glass in it

Transconductance measured 1975/2150 micromhos for Tube One and 2000/2200 micromhos for Tube Two

46 and 49 where minimum (65%) is 30 and 100% is 47

(New US-made 6V6s typically test with plate current from the mid-teens to mid 30s with transconductance from 2300 micromhos or so

This is a new old stock

Transconductance readings are 15

This matched pair of GE 12B4A tubes was tested on our Paul Hart-calibrated TV7/U for shorts

This tube has triple mica spaces and two additional support rods for vibration and microphonics suppression

Tube One measured 33 while Tube Two measured 34 where minimum (65%) is 32 and 100% is 49

I am playing them with adapters (not included) in my Radio Craftsmen RC-2 monoblocks and they sound great even though they test on the cusp

They sound spacious with excellent dynamic range and frequency response on these challenging pieces -- and are dead quiet when the CD player is muted

they can put out as much as 2A3s and fell into disfavor because of socket supply issues